Sump pump control



Jan. 10, 1956 A. L. NIELSEN SUMP PUMP CONTROL Filed Aug. 5. 1955 INVENTOR.

AXEL L. NIELSEN BY [V ATTORNE 5 United States Patent SUMP PUMP CONTROL Axel L. Nielsen, Hazel Park, Mich.

Application August 3, 1953, Serial No. 372,132 9 Claims. (Cl. 200-84) The present invention relates to a float and pressure switch particularly designed for use in controlling a sump pump.

One of the objects of the present invention is to provide a sump pump control device which will be effective to operate a switch to initiate action of a motor controlling a sump pump when the level of water in the sump reaches a predetermined level and which is effective thereafter to maintain the switch closed until all of the water in the sump has been pumped out.

It is a further object of the present invention to provide a sump pump control device of the character described employing an air pressure chamber from which liquid from the sump is excluded, operatively connected to the discharge line of the sump pump so that so long as liquid is being pumped, pressure in the pressure chamber will maintain the switch closed.

It is a further object of the present invention to provide in a sump pump control device of the character described a novel construction employing a pair of relatively large diaphragms arranged to be acted upon by the pressure of the liquid being pumped and connected so as to oppose each other.

It is a further object of the present invention to provide a float controlled pressure responsive sump pump control device.

It is a further object of the present invention to provide a sump pump control device as described in the preceding paragraph which is provided with adjustable spring means opposing upward movement of the float.

It is a further object of the present invention to provide a sump pump control device as described in the foregoing comprising adjustable means for varying the lower position of the float.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, wherein:

Figure 1 is a vertical section through a sump pump control device constructed in accordance with the present invention.

Figure 2 is a vertical section through a sump pump control device employing a different type of switch mechanism.

Referring first to Figure l, the sump pump control device comprises a switch housing indicated generally at formed of a main body 12 having at its top an outwardly extending flange 14 and a cover 16 and having at its bottom an outwardly extending flange 18 bolted of otherwise secured to the flange 14 by fastening elements 20. The cover 16 includes tapped openings 22 adapted to receive electrical conductors 24 and threaded members 26 forming a tight seal with the conductors 24 and cover 16. 7

Located within the switch housing 10 is a switch which is illustrated herein as a mercury switch 28 having spaced contacts at one end adapted to be bridged by mercury when such end of the switch is in lower position. It will be appreciated that the electrical conductors 24 are suitably connected to the switch and to a sump pump control motor so that when the switch 28 is closed the motor is energized.

The main body 12 of the switch housing is shaped to provide a continuous upwardly facing shoulder 30 and on this shoulder is secured a mounting plate 32. The central portion of the mounting plate 32 is upwardly bowed as indicated at 34 and is provided with a central opening 36 for a purpose which will presently appear.

Below the shoulder 30 the main body 12 of the switch housing includes a downwardly and inwardly inclined wall 38.

Mounted on the shoulder 30 is an upper flexible diaphragm 46 the peripheral portions of which are sealingly clamped in place by peripheral portions of the mounting plate 32. The main body 12 is provided with a bottom closure member 42 and a second flexible diaphragm 44 has its peripheral portions clamped to the bottom of the main body 12 by the member 42. There is thus provided an air pressure chamber 46 closed at its top by the flexi'ule diaphragm 40, at its bottom by the flexible diaphragm 44, and laterally by the inclined surface 38 of the body 12. As a result of the above described construction and as is apparent from an inspection of the figure, the area of the diaphragm 40 exposed to pressure within the air pressure chamber 46 is larger than the area of the diaphragm 44 which is exposed to pressure within such chamber. Accordingly, when pressure exists within the chamber 46 there is a resultant upward force applied to structure connected to the diaphragms.

The mounting plate 32 has upwardly projecting ears 5i to which the switch supporting bracket 52 is pivotally mounted, as indicated at 54. The axis of the pivot 54 is located toward one end of the bracket 52 so that due to gravity the bracket 52 and switch 28 tend to assume the illustrated position.

The bottom closure member 42 is provided with a downwardly extending tubular portion 56 which is internally threaded as indicated at 58 and which receives a short section of an externally threaded tube 60. The bottom portion of the tube is formed with a head 62 which may be square, hexagonal, or other shape, by means of which the tube may be threaded into the opening 58 and adjusted vertically therein. A suitable lock nut 64 is provided adapted to bear against the underside of the tubular portion 56 of the bottom closure member 42 to lock the tube 66 in adjusted position.

Longitudinally slidable through the tube 60 is a float rod 66 having its lower end threaded as indicated at 68 and threadedly engaged in a float member 70. A lock nut 72 is provided to prevent separation between the float rod 66 and the float 70. provided which surrounds a portion of the float rod intermediate the float 78 and the lower end of the tube 60. The upper end of the spring 74 engages the head 62 of the tube 63. The lower end of the spring bears against a pressure adjusting nut 76 threaded to the lower end of the rod 66 and retained in position by a lock nut 78.

The pressure of the spring 74 may of course be adjusted by loosening the lock nut 78 and effecting the required movement of the pressure adjusting nut 76.

The float rod 66 extends upwardly through aligned openings in the diaphragms 40 and 44 and the upper end of the float rod engages the underside of the bracket 52 as indicated at 80. The interconnection between the float rod 66 and the diaphragms 40 and 44 is completed by a spacing collar 82, washers 84 and 86, and nuts 88 and 90.

It will be observed that when the float 70 is in its lowermost position the nut 90 engages the upper end of the tube A compression spring 74 is.

60 which thereby constitutes an adjustable stop determining the position of the switch 28 when the float and float rod are in their lowermost position. This permits a fine adjustment of the switch. The bracket 52 may be provided wth a portion 92 engageable with the side wall of the housing 12 to limit rocking movement of the bracket 52 in one direction. Preferably however, the upper washer 86 is somewhat larger than the opening 36 and thereby constitutes an abutment directly limiting upward movement of the float rod 66.

The main body 12 of the switch housing is provided with a tapped opening 94 which receives a tubular member 96, the other end of which is connected to the discharge pipe 98 through which the sump pump discharges water from the sump. In accordance with the present invention the tubular member 96 is connected to the discharge pipe 98 at a point indicated at 100, substantially below the horizontal level of the opening )4. Accordingly, as pressure develops in the pipe -98 as a result of operation of the sump pump, water flows into the tubular member 8'6 and compresses the air therein and in the air chamber 46. The air chamber and adjacent portion of the tubular portion 96 thereby constitutes an air trap and prevents entrance of liquid into the chamber 46. This is an important feature of the present invention since liquid discharged by a sump pump often contains silt or other particles which it allowed to accumulate within the control mechanism would eventually interfere with its successful operation.

One of the important advantages of the present construction resides in the use of the relatively large opposed diaphragms 4t and 44 since by using a pair of opposed diaphragms it is possible to employ relatively large diaphragms with resultant freedom of movement and avoidance of fatigue and the like. At the same time the resultant force exerted on the float rod 66 is determined by the difference in area between the diaphragms and this may be as small as required.

Another very important advantage in the present construction is in the use of the adjustable spring means for biasing the float downwardly. in some sump pump systerns a pump is provided which when its operation is terminated, may prevent a return flow of liquid remaining in the pipe or which may permit such return flow only in a very restricted manner. The present sump pump control device is intended to initiate operation of the sump pump when the level in the sump reaches a predetermined level and to continue the operation of the sump pump so long as liquid remains in the sump. The operation of the sump pump motor is continued during the pumping operation by the pressure within the pipe 98 which is eflectivc within the air chamber 26 to maintain the float rod in its uppermost position and hence to maintain the switch 23 closed. When the sump pump has discharged all of the water from the sump into the pipe )8 pressure within the pipe diminishes to some predetermined value and by proper adjustment of the spring 74 the float rod 66 may be forced downwardly to permit opening of the switch 28. In some cases however, the pressure within the pipe 98 may tend to remain at a value not much less than that attained during normal pumping operation, at least for a considerable time. By providing the adjustable spring 74 the sump pump control device may be adjusted to insure cutting off the sump pump motor upon a very small reduction in pressure within the pipe 98 which will take place when all of the liquid has been pumped from the sump by the sump pump.

Referring now to Figure 2 there is illustrated a similar arrangement which differs primarily in the substitution of a switch 110 having a button or operating plunger H2 en gaged directly by the upper end of the float rod 66. The

switch 110 is secured to a mounting bracket lid which in turn is secured to the upwardly domed mounting plate illustrated in this figure at 116.

The drawings and the foregoing specification constitute a description of the improved sump pump control device lit) til)

in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

l. A sump pump control device comprising a pair of spaced flexible diaphragms, sealing means connecting peripheral portions of said diaphragms and defining therewith a pressure-responsive enclosure, one of said diaphragms having a larger area exposed to pressure within said enclosure than said other diaphragm, a float rod operatively connected to both of said diaphragms, a float on said rod, and a sump pump motor control switch operatively connected to said rod, and conduit means connecting said enclosure to the discharge line of a sump pump to exert on said float rod a force equal to the difference between the forces developed on said diaphragms by pressure within said enclosure.

2. A device as defined in claim 1 in which said conduit is connected to said discharge line substantially below said enclosure to entrap air and prevent the entrance of pumped liquid into said enclosure.

3. A device as defined in claim 1 which comprises adjustable resilient means opposing upward movement of said rod.

4. A device as defined in claim 1 in which said diaphragms are horizontal, said rod extends through and is scaled to said diaphragms, and said switch is located above and operated by the upper end of said rod.

5. A sump pump control device comprising a switch housing having therein a switch for controlling a sump pump motor, said housing having an opening at its bottom, a pair of spaced horizontal flexible diaphragms closing the lower end of said housing and defining therewith a pressure chamber intermediate said diaphragms, said housing having an opening intermediate said diaphragms for connection to the discharge line of a sump pump, an aperlured closure plate extending across the bottom of said housing below the lower one of said diaphragms, a tube vertically adjustable in the aperture of said plate, a float rod connected intermediate its ends to both of said diaphragms and extending downward through Said tube, a float on the lower end of said rod, a spring abutment on the lower end of said tube, a spring abutment on said rod, one of said abutments being vertically adjustable, a compression spring extending between said abutments, the upper id of said rod extending above the upper one of said diaphragms and operatively connected to said switch.

6. A device as defined in claim 5, the upper end of said tube being engageable by means connected to said rod to constitute an adjustable abutment determining a limited position of the upper end of the float rod and thereby providing for adjustment of switch actuation.

7. A sump pump control device comprising a pair of spaced flexible diaphragms, sealing means connecting peripheral portions of said diaphragms and defining therewith a pressure-responsive enclosure, one of said diaphragms having a larger area exposed to pressure within said enclosure than said other diaphragm, means connecting the central portions of said diaphragms together, a switch actuator operatively connected to said diaphragms, float mechanism including a float operatively connected to said diaphragms, spring means operatively connected to said float mechanism to oppose upward movement of said float, and means for connecting said enclosure to pressure prevailing in the sump pump discharge line.

8. A device as defined in claim 7 in which said last mentioned means comprises a conduit extending downwardly from said enclosure to entrap air therein and prevent entrance of liquid into said enclosure.

9. A sump pump control device comprising a pair of spaced flexible diaphragms, sealing means connecting peripheral portions of said diaphragms and defining therewith a pressure-responsive enclosure, one of said diaphragms having a larger area exposed to pressure within said enclosure than said other diaphragm, means connecting the central portions of said diaphragms together, a sump pump motor switch, a switch actuator operatively connected to said diaphragms, means responsive to depth of liquid in a sump to move both of said diaphragms to close said switch, means for connecting said enclosure to the sump pump discharge line, and adjustable spring means operatively connected to said switch actuator to adjust the pressure within said enclosure at which said switch is opened.

References Cited in the file of this patent UNITED STATES PATENTS 

